BORIS Johnson today proudly declared Britain had "proved the Olympo-sceptics wrong", as it was revealed the 2012 London Olympic and Paralympic Games UK boosted the British economy by an incredible £9.9 billion.

The UK economy has seen a £9.9bn boost in trade and investment from hosting the 2012 London Games

After hosting the 2012 Games, the country saw a massive boost in trade and investment from businesses securing contract wins, additional sales and new foreign investment in the last year, said a new report from the Government.

The total benefit to the UK could be between £28bn and £41bn by 2020, independent estimates cited in the report suggested.

The report said strong progress had been made against all the legacy commitments including an increase in volunteering – halting the steady decline seen since 2005.

London Mayor Boris Johnson said London put on a world class Games

Boris Johnson was very involved in the running of the 2012 London Olympics

Additionally, since the spectacular summer of sport, 1.4 million more people are now playing sport at least once a week than in 2005 when the bid was won and the legacy of all the permanent venues on the Olympic Park secured within a year of the Games.

"We proved the Olympo-sceptics in error when they declared that London couldn't lay on a world class Games," London Mayor, Mr Johnson said today.

"We are now set to defy the doom-mongers when it comes to securing a permanent legacy.

"London is succeeding where virtually no other host city has, on track to secure a solid gold payback on the taxpayers' outlay and a rosy future for the Queen Elizabeth Olympic Park.

Since last summer, he said, the capital has seen a surge in overseas investment this is "delivering tens of thousands of jobs not only in London but spurring growth across the UK and helping the country sprint ahead in the global race for business."

The total benefit of the Games to the UK will be between £28bn and £41bn by 2020

Andy Murray with his Gold medal after his victory in the Mens Singles Final over Roger Federer

Prime Minister David Cameron said that the new report highlighted the important legacy of the Olympic Games, which would "help make Britain a winner in the global race."

"This £9.9 billion boost to the UK economy is a reminder to the world that, if you want the best, if you want professionalism, if you want jobs done on time and on budget then you should think British.

Mr Cameron added companies across the country were "harnessing the Olympic momentum and delivering the lasting business legacy of the Games".

"But that's not where the good news ends," he continued. "The Games are also delivering a strong social legacy. Last summer, Games Makers changed the way Britain views volunteering.

"Since then, thousands of people have been inspired to get involved with their local sports clubs."

Prime Minister David Cameron said companies across the country were harnessing the Olympic momentum

The Games also delivered a strong social legacy

Business Secretary Vince Cable also emphasised that there was no doubt the 2012 Games has "proved a success story for British business."

"This has created a multi-billion pound business springboard to take British expertise to the world, and UKTI (UK Trade and Investment) is working hard to make the most of this significant opportunity," he said.

"Reaching £9.9bn in the space of one year is an amazing achievement.

"I hope that companies of all sizes up and down the country follow suit and use the positive impact generated by the Games to reach out to new markets and grow their businesses."